1. Following the reported transaction, includes: (i) 15,968,418 shares of common stock held by Onex Partners II LP; (ii) 10,735,459 shares of common stock held by Onex Allison Holding Limited S.a R.L.; (iii) 7,527,479 shares of common stock held by Onex Allison Co-Invest LP; (iv) 300,828 shares of common stock held by Onex US Principals LP; and (v) 150,086 shares of common stock held by Onex Partners II GP LP.

2. Onex Corporation may be deemed to beneficially own the common stock held by (a) Onex Partners II LP, through Onex Corporation's ownership of all of the common stock of Onex Partners GP Inc., the general partner of Onex Partners II GP LP, the general partner of Onex Partners II LP; (b) Onex Allison Holding Limited S.a R.L., through Onex Corporation's ownership of all of the equity of Onex American Holdings II LLC, which owns all of the equity of each of Allison Executive Investco LLC, which owns all of the equity of Allison Executive Investco II LLC, and Onex American Holdings Subco LLC, which owns all of the equity interests of OAH Wind LLC, which OAH Wind LLC and Allison Executive Investco II LLC own all of the equity interests of Onex Allison Holding Limited S.a R.L.; (continued)

3. (c) Onex Allison Co-Invest LP, through Onex Corporation's ownership of all of the common stock of Onex Partners GP Inc., the general partner of Onex Partners II GP LP, the general partner of Onex Allison Co-Invest LP; (d) Onex US Principals LP, through Onex Corporation's ownership of all of the equity of Onex American Holdings II LLC, which owns all of the equity of Onex American Holdings GP LLC, the general partner of Onex US Principals LP; and (e) Onex Partners II GP LP, through Onex Corporation's ownership of all of the common stock of Onex Partners GP Inc., the general partner of Onex Partners II GP LP.

4. New PCo II Investments Ltd. is the record holder of 637,794 shares of common stock and 1,185 shares of non-voting common stock. 1597257 Ontario Inc., the sole shareholder of New PCo II Investments Ltd., is an independent entity that is controlled by Mr. Gerald W. Schwartz. Mr. Schwartz, the Chairman, President and Chief Executive Officer of Onex Corporation, owns shares representing a majority of the voting rights of the shares of Onex Corporation and as such may be deemed to beneficially own all of the common stock owned beneficially by Onex Corporation. Mr. Schwartz disclaims any such beneficial ownership. Mr. Schwartz has indirect voting and investment control of Onex Corporation.